Double- vs. single-injection infraclavicular plexus block in the emergency setting: higher success rate with lower volume of local anaesthetic

BACKGROUND AND OBJECTIVES: Infraclavicular plexus block has many advantages of particular interest in the emergency setting. However, the number of nerve stimulations needed to optimize the technique remains unclear. We evaluated both the local anaesthetic requirement and the success rate of Sim's derived infraclavicular plexus block performed with a nerve stimulator when either one or two responses were sought. METHODS: In this prospective study, 50 patients who presented for distal upper limb surgery were randomized into two groups: in Group 1, ropivacaine 0.75% 40 mL was injected when nerve stimulation elicited a distal motor response (median, ulnar or radial). In Group 2, only 30 mL of the same local anaesthetic was injected, 7 mL to the musculocutaneous nerve and 23 mL to the median, ulnar or radial nerves. Sensory and motor blocks were tested at 5-min intervals over 30 min. RESULTS: The time to perform the block was similar in both groups. The success rate of the block increased from 80% in the single-stimulation group to 92% in the double-stimulation group (not significant). The onset time of sensory and motor block was shorter and block extension was greater in ulnar, antebrachial cutaneous and brachial cutaneous nerve distributions in the multistimulation group (P < 0.05). CONCLUSIONS: We conclude that only 30 mL of local anaesthetic seems to be sufficient to ensure a high level of success when performing an infraclavicular block with stimulation of both the musculocutaneous nerve and median, ulnar or radial nerve.     

Infraclavicular block causes less discomfort than axillary block in ambulatory patients

BACKGROUND: This randomized study was designed to compare discomfort caused by axillary or infraclavicular blocks in ambulatory patients. We identified which of the three block components, needle passes, local anesthetic (LA) injections, and electrical stimulations, is most painful and quantified pain intensity on a visual analog scale (VAS 0-100). We also assessed onset and quality of analgesia, adverse events and patients' acceptance. METHODS: Eighty patients were studied. In axillary group-A, four LA injections were made after stimulating median, musculocutaneous, ulnar and radial nerves. In infraclavicular group-I, the whole LA volume was injected after stimulating median or ulnar or radial nerves. Patients were ready for surgery when they had analgesia/anesthesia distal to the elbow. RESULTS: Median intensity of block discomfort was 22 in A group and 10 in I group (P < 0.01). There was no difference in distribution of the most painful block components between the groups. Block performance times were 4 min in I group and 7 min in A group (P < 0.01). Block onset times were 18 min in A group and 20 min in I group (NS). There was one block failure in I group. Three patients in A group and five in I group required supplementary blocks (NS). Transient adverse events occurred in 14 A-group and two I-group patients (P<0.01). Thirty-seven I-group and 33 A-group patients were satisfied with the block (NS). CONCLUSIONS: Infraclavicular block by single injection caused less discomfort and fewer adverse events than axillary block by multiple injections. Block effectiveness, onset time and patients' acceptance were similar.     

超声引导下不同入路臂丛神经阻滞在桡骨远端手术中效果的比较

目的 比较超声引导下不同入路臂丛神经阻滞(肌间沟、腋路、锁骨上)在桡骨远端手术中的麻醉效果. 方法 90例择期行“桡骨远端骨折切开复位内固定术”或“桡骨远端骨折术后内固定取出手术”的成年患者,在超声引导下行臂丛神经阻滞,按照随机数字表法分为3组(每组30例):肌间沟入路臂丛神经阻滞组(A组)、腋路臂丛神经阻滞组(B组)、锁骨上入路臂丛神经阻滞组(C组).记录操作时间、镇痛持续时间,测定桡神经、尺神经、正中神经、前臂外侧皮神经和前臂内侧皮神经分布区的痛觉消失时间,评价感觉阻滞效果、麻醉效果及并发症的发生情况. 结果 3组患者基本资料与操作时间比较,差异无统计学意义(P＞0.05).3组的镇痛持续时间差异无统计学意义(P＞0.05).3组桡神经、正中神经、前臂外侧皮神经痛觉消失时间差异均无统计学意义(P＞0.05).A组和C组患者尺神经痛觉消失时间比较[(21±6) min比(20±5) min],差异无统计学意义(P＞0.05),但均长于B组[(8±5)min](P＜0.05);A组和C组前臂内侧皮神经痛觉消失时间比较[(18±6) min比(17±6) min],差异亦无统计学意义(P＞0.05),但与B组[(10±6) min]比较,差异均有统计学意义(P＜0.05).B组麻醉效果优秀率最高(90％).A组和C组分别有2例和1例患者出现膈神经阻滞,B组有1例患者止血带不耐受. 结论 超声引导下腋路臂丛神经阻滞时尺神经及前臂内侧皮神经痛觉消失时间短,在桡骨远端手术中麻醉优秀率高、并发症少.     

Nerve blocks at the wrist for carpal tunnel release revisited: the use of sensory-nerve and motor-nerve stimulation techniques

BACKGROUND AND OBJECTIVES: Because the median nerve at the wrist has mainly sensory endings, the aim of this study was to assess the response of the median nerve to nerve stimulation at the wrist and to evaluate the quality of median nerve block. A control group of patients who received blinded injections was analyzed and compared post hoc. METHODS: One hundred and eleven patients scheduled for ambulatory endoscopic carpal-tunnel release performed under median and ulnar nerve blocks at the wrist were prospectively studied. The blocks were performed with a nerve stimulator. Nerve-stimulation techniques were explained to the patient before the block was performed. The patient was trained to inform the anesthetist of their perception of an electrical paresthesia that was synchronized to the nerve stimulator. The anesthetist recorded the first response of the patient to nerve stimulation: sensory (S), sensory-motor (SM), or motor response (M). When the minimal stimulating current was obtained, an equal volume of 4 mL of 1.5% mepivacaine was injected on median and ulnar nerves. If necessary, a lateral subcutaneous injection of 2 mL of 1.5% mepivacaine was administered at the wrist crease in the musculocutaneous nerve area. Thirty-five patients who received blinded local anesthetics injections were included post hoc. Quality of anesthesia was compared between groups. RESULTS: Responses included 89 S (80.2%), 18 SM (16.2%), and 4 M (3.71%). No differences occurred in time to perform the block, minimal current intensity, and efficacy. More punctures were necessary in the M group compared with the S group and the control group (P < .05). The onset time of sensory blocks increased significantly in control-group patients (P < .05), but the duration of the nerve-block procedure decreased in comparison with the M group. Respectively, 10% and 20% of patients experienced mild or severe pain in the nerve-stimulation group and control group. At 20 minutes, the block was complete for the median and ulnar nerves in 96.4% and 85% of the nerve-stimulation patients and control patients (P < .05). Two patients in the control group experienced painful mechanical paresthesia. Neither permanent nor transient nerve injuries were observed during or after the nerve block or surgery. CONCLUSION: This study describes how infrequently an initial motor response is identified when a nerve stimulator is used on the median nerve at the wrist. A very high success rate of median and ulnar nerve block at the wrist is obtained by use of sensory or sensory-motor-nerve stimulation and less than 10 mL of anesthetic solution.     

超声引导下锁骨上入路单靶点或三靶点注射法臂丛神经阻滞的效果

目的 比较超声引导下锁骨上入路单靶点和三靶点注射法与传统解剖定位法臂丛神经阻滞的效果.方法 择期拟行上肢手术患者90例,性别不限,ASA Ⅰ或Ⅱ级,随机分为3组(n=30):单靶点组(S组)超声引导下锁骨上臂丛神经周围注射21 ml局麻药;三靶点组(T组)超声引导下在锁骨上臂丛神经与锁骨下动脉相接位置的下方注射7 ml局麻药,再2次(各7 ml)调整穿刺针的位置形成以臂丛神经为中心的扇形注射;传统解剖定位组(A组)取锁骨中点上1 cm左右为穿刺点,注射21 ml局麻药.局麻药为0.375%罗哌卡因和1%利多卡因的混合液.记录各组操作时间和尺神经、正中神经、桡神经支配区域痛觉消失时间及镇痛持续时间;评价各神经支配区域的阻滞程度及切皮时的麻醉效果,观察并发症的发生情况.结果 与A组相比,T组操作时间延长,尺神经分支配区域痛觉消失时间缩短,S组和T组麻醉效果满意率升高,镇痛持续时间延长,尺神经、正中神经的阻滞完全率升高(P＜0.05);与T组相比,S组操作时间缩短,尺神经分支配区域痛觉消失时间延长(P＜0.05);三组桡神经阻滞完全率差异无统计学意义(P＞0.05).A组刺破血管4例,轻度局麻药中毒1例,S组和T组未见并发症发生.结论 与传统解剖定位法相比,超声引导下锁骨上臂丛神经阻滞的单靶点和三靶点注射法麻醉效果较好、镇痛持续时间较长,且并发症较少;三靶点注射法的操作时间较单靶点注射法长,但对尺神经的阻滞较快且完全.     

A comparison of coracoid and axillary approaches to the brachial plexus

BACKGROUND: Brachial plexus block by the coracoid approach does not require arm abduction and may be more effective than the axillary approach because of a more proximal injection of local anaesthetic. However, the clinical usefulness of the coracoid approach has not been tested in prospective controlled trials. The present randomized, observer-blinded study compared success rates, time to obtain a complete block, frequency of adverse effects and block discomfort in two groups of 30 patients, anaesthetized for hand surgery using either the coracoid or the axillary approach to the brachial plexus. METHODS: After subcutaneous infiltration with 5 ml of 1% mepivacaine/adrenaline the brachial plexus was located using a nerve stimulator and an insulated pencil-point needle. Ropivacaine 0.75%, 20-40 ml, depending on body weight, was used for the initial block. In the coracoid (C) group two plexus cords, and in the axillary (A) group four terminal nerves were electrolocated and the volume of ropivacaine was divided equally between them. Spread of analgesia to the arm was assessed every 5 min, by an anaesthetist unaware of the block technique. The block was defined as effective (complete) when analgesia was present in all five sensory nerve areas distal to the elbow. Incomplete blocks were supplemented 30 min after the initial block. RESULTS: In the C group a median 11 min was required for block performance as compared to 12 min in the A group (NS). Onset of block was shorter and the frequency of incomplete blocks lower in the A group (median 17 min and 17%) than in the C group (30 min and 47%, respectively). Lack of analgesia of the ulnar nerve was the main cause of incomplete initial blocks in the C group. All incomplete blocks were successfully supplemented. However, total time to obtain complete block was shorter in the A group than in the C group (29 min vs. 41 min, P<0.05). Accidental arterial puncture occurred in seven patients (five in C and two in A group), which resulted in two haematomas, both in the C group (NS). No permanent sequelae were observed. CONLCUSION: The axillary approach to the brachial plexus using four injections of ropivacaine results in a faster onset of block and a better spread of analgesia than the coracoid approach using two injections.     

Double-injection method using peripheral nerve stimulator is superior to single injection in axillary plexus block

BACKGROUND AND OBJECTIVES: Axillary block using a single-injection method does not always provide effective analgesia. This study examined whether a double axillary block injection technique is superior to a single injection axillary block. METHOD: Fifty patients were randomly allocated to two groups. In group I (single injection), the whole volume of local anesthetic (0.7 mL/kg) was injected after locating only one of the median, radial, or ulnar nerves. In group 2 (double injection), half of the volume was injected after locating one nerve and the other half after locating another peripheral nerve. Bupivacaine 0.5% and prilocaine 1% (1:1 volumes) were used as local anesthetic. A peripheral nerve stimulator was used to identify the nerves. Sensory block of seven nerves and motor block of four nerves were tested after 40 minutes. RESULTS: Complete sensory and motor block (scores 2 or 3 on scale 0-3) in all four main nerves (median, ulnar, radial, musculocutaneous) was achieved in 3 (12%) versus 20 (80%) patients in groups 1 and 2, respectively (P = .000001). Primary success rate (no need for supplemental nerve block) was 52% in group 1 and 92% in group 2 (P = .0016). CONCLUSIONS: A double-injection method in axillary block provides excellent analgesia and motor block compared with a single-injection method. Moreover, the need for supplemental nerve blocks is significantly decreased.     

A comparison of the vertical infraclavicular and axillary approaches for brachial plexus anaesthesia

BACKGROUND: This prospective, randomized study compared the efficacy of the vertical infraclavicular and axillary approaches using a single injection blockade of the brachial plexus. The primary endpoint was complete blockade in dermatomes C5-Th1, while secondary endpoints included onset time, motor block, block performance time, surgical success rate, patient satisfaction, and side-effects/complications. METHODS: Sixty patients, American Society of Anesthesiologists physical status I or II, scheduled for surgery of the forearm or hand received either a vertical infraclavicular (n = 30) or an axillary block (n = 30). A single injection of 0.5 ml/kg ropivacaine 7.5 mg/ml was made after electrolocalization of nerve fibres corresponding to the median nerve at maximum 0.5 mA (2 Hz, 0.1 ms). Onset and distribution of analgesia and motor block were assessed at 5, 10, 15, 20, 30 and 60 min after the local anaesthetic injection. A complete block was defined as analgesia in all dermatomes (C5-Th1) at 60 min post-injection. RESULTS: The vertical infraclavicular approach provided complete blockade in 29 patients (97%) and the axillary approach in 23 patients (77%). Analgesia in C5-C6 dermatomes and corresponding motor block occurred significantly more frequently in the vertical infraclavicular approach, which also had the shortest onset time. Block procedure was quicker in the axillary approach. Side-effects were similar in both groups, and there were no permanent sequelae. Patient satisfaction was equally high in both groups. CONCLUSION: The vertical infraclavicular approach provides a more complete block than the axillary approach when using a single injection technique and equal volumes/doses of local anaesthetic.     

Leitungsblockaden beim Menschen sind stimulationsfrequenzabhängig

The action of local anaesthetics on isolated nerves is enhanced by high stimulation frequencies. The aim of our study was to investigate whether high-frequency stimulation enhances regional anaesthesia in man. Methods. Seven healthy volunteers underwent three ulnar nerve blocks while non-noxious electrical stimulation with high (10, 50 Hz) or low (0.2 Hz) frequencies was applied via a widespread cutaneous electrode in the area supplied by the ulnar nerve. Perception was monitored continuously by means of a visual analogue scale. Skin temperature (infrared telethermometry) was evaluated every minute as an indicator of vasomotor block. After complete loss of perception or after 45 min, the spread of anaesthesia was determined by sharp-dull discrimination. The nerve block was preceded by a control stimulation of 45 min under otherwise identical conditions. Results. During stimulation with 10 and 50 Hz, perception was lost significantly earlier than with 0.2 Hz. The spread of sensory block at the end of the experiments was also enhanced by stimulation with high frequencies, whereas the onset of vasomotor block (rise in skin tempeature) remained unaltered. Conclusion. Non-oxious electrical stimulation with high frequencies significantly accelerates the onset of anaesthesia and extends the spread of sensory block.     

超声引导下锁骨上臂丛神经阻滞方法的研究

目的：将超声引导下锁骨上臂丛神经阻滞的单靶点和三靶点注射法与传统解剖定位法进行比较从而探讨单靶点和三靶点注射法阻滞的可行性及临床效果。方法：90例上肢择期手术患者,ASAI～Ⅱ级,随机分为．21ml单靶点注射组（单靶组）．7ml三靶点注射组（三靶组）,21mi传统解剖定位组（传统组）,局麻药为0.375％罗哌卡因和10％利多卡因的混合液记录各组的操作时间、麻醉镇痛持续时间、以及尺神经、正中神经、桡神经分布区痛觉消失的时间,评价各神经支配区域的痛觉阻滞程度（完全、部分、缺乏阻滞）和切皮时麻醉效果（优秀、良好、无效）,观察并记录并发症。结果：单靶组和传统组的操作时间较三靶组短（P〈0.05）,单靶组和传统组的尺神经痛觉消失时间较三靶组长（P〈0.05）与传统组相比单靶组和传统组麻醉效果的优秀率较高（P〈0.05）麻醉镇痛持续的时间延长（P〈O05）尺神经、正中神经的阻滞完全率较高（P〈0.05）而桡神经阻滞完全幸的比较三组无明显差异（P〉0.05）。单靶组和三靶组均无并发症传统组剌破血管4例,轻度局麻药中毒1例。结论：与传统解剖定位法相比,超声引导下锁骨上臂丛神经阻滞的单靶点和三靶点注射法麻醉效果较好、镇痛持续时间较长及并发症较少。三靶点注射法的操作时间较单靶点注射法长,但对尺神经的阻滞较快且较完全。     

A comparison of injection at the ulnar and the radial nerve in axillary block using triple stimulation

BACKGROUND AND OBJECTIVES: A triple-stimulation technique for axillary block consists of the localization and injection of 2 nerves, median and musculocutaneous, which lie superior to the axillary artery, and of 1 nerve, the radial, which lies inferior. However, in some patients, the ulnar nerve is located first during the search for the radial nerve. The aim of this study was to verify if an ulnar motor response could be considered a satisfactory endpoint as a radial motor response. METHODS: This study was a prospective, randomized, double-blinded study. Ninety patients received a triple-injection axillary brachial plexus block in which the radial nerve (group RAD) or the ulnar nerve (group ULN) was located and injected inferior to the axillary artery. Patients were assessed for sensory and motor block by a blinded investigator at 5-minute intervals over 30 minutes. RESULTS: A statistically significant higher overall block success rate was recorded in group RAD (91% vs. 73%), and this result was related to a larger success rate for anesthetizing the radial nerve (95% vs. 77%). A statistically significant shorter onset time of sensory block for the radial nerve was recorded in group RAD versus group ULN (9 +/- 5 min vs. 16 +/- 7 min), whereas the reverse was true for the ulnar nerve (13 +/- 7 min for group RAD vs. 10 +/- 3 min for group ULN). The time to perform the block was slightly but statistically significantly shorter in group ULN (6.5 +/- 1.7 min vs. 7.8 +/- 1.8 min). CONCLUSIONS: Local anesthetic injection at the ulnar nerve significantly reduces the efficacy and prolongs the onset time of the radial-nerve block when triple-stimulation axillary block is performed.     

Use of ultrasound guidance and contrast enhancement: a study of continuous infraclavicular brachial plexus approach

Purpose: We describe our experience of combining the use of ultrasound (US) guidance with contrast enhancement and peripheral nerve stimulation for the insertion of infraclavicular brachial plexus catheters. Methods: Thirty patients scheduled to have upper limb surgery under regional block were studied. Under US guidance and peripheral nerve stimulation assistance, continuous peripheral nerve block needle and stimulating catheter were placed in the infraclavicular area. Needle and catheter tip location was confirmed with agitated 5% dextrose and seen under colour Doppler with US before injecting local anaesthetic (LA). Patients were evaluated in terms of onset times and efficacy of block. Post‐operatively, on block recession a catheter was stimulated and visualization of spread of LA during injection through the catheter was done. Secondary block (subsequent to re‐injection of LA) was assessed. Patients were followed‐up for a week. Results: Mean time to onset of block was 19.7 (± 4.9) min. There were no incomplete blocks and all components of the plexus were blocked completely. Post‐operatively, in 95.7% of patients, the spread of hand‐agitated LA via the catheter could be seen by color Doppler with ultrasonography. All patients had excellent post‐operative analgesia and high degree of satisfaction. There were no complications. Conclusion: Contrast enhancement with US guidance during infraclavicular brachial plexus block enables direct visualization of needle and catheter tip location. Our early experience suggests that this leads to successful initial and subsequent post‐operative block. Further controlled studies are needed to compare this technique with more prevalent and conventional techniques of catheter insertion.     

Response to single twitch or single burst stimulation of the ulnar nerve as predictive guide for intubating conditions

Disappearance of response to single twitch stimulation (STS) or train-of-four stimulation (TOF) of the ulnar nerve is insufficient as predictive guide for intubating conditions during onset of non-depolarizing neuromuscular block. Double burst stimulation (DBS) appears to be a more reliable indicator of the optimal time for intubation. In the present study, the disappearance of tactile detectable response to 0.1 Hz single twitch stimulation (STS) of the ulnar nerve was compared with disappearance of response to 0.1 Hz single burst stimulation (three stimuli at 50 Hz=SBS) as predictor for optimal intubating conditions during onset of block induced by 0.08 mg . kg^-1 of vecuronium in 100 patients under light general anaesthesia where thiopentone was used as the sole anaesthetic. Intubation was performed immediately after disappearance of the twitch response. Likewise 0.05 Hz STS and 0.05 Hz SBS stimulation were compared under identical circumstances in another 100 patients. Intubating conditions were unacceptable in 10%, 14%, 8% and 10% of the patients in the 0.1 Hz STS, 0.1 Hz SBS, 0.05 Hz STS and 0.05 Hz SBS groups, respectively. There were no significant differences between the groups. In conclusion, neither absence of response to STS stimulation nor absence of response to SBS stimulation of the ulnar nerve at either 0.1 Hz or 0.05 Hz frequency does guarantee acceptable intubating conditions during onset of neuromuscular block induced by vecuronium 0.08 mg . kg^-1 when thiopentone is used as the sole anaesthetic.     

Abordaje ecoguiado a nivel antecubital para cirugía del síndrome del túnel del carpo

IntroductionThere are various anaesthetic techniques for ambulatory surgery of carpal tunnel release. The ultrasound-guided nerve blocks offer advantages compared to other techniques. The purpose of this study was to evaluate the efficacy using ultrasound-guided block at the antecubital fossa, as well as to evaluate complications, patient satisfaction and surgeon satisfaction with the block.Materials and methodsProspective observational study with 32 elective patients for carpal tunnel release in a one-day case unit. An ultrasound-guided block with mepivacaine 1% was performed at the antecubital fossa, aiming for the median, ulnar and the lateral and medial cutaneous nerves of the forearm. The measurements of the anteroposterior and laterolateral diameters of the median and ulnar nerves were recorded, before and after injection. Motor and sensory levels were evaluated for the median and ulnar nerves at 5 and 30 min post injection, and compared with the contralateral hand. Pain from the surgical incision time and recovery were recorded, together with complications, and patient and surgeon satisfaction with the block.ResultsThe antecubital fossa ultrasound-guided block was successful in 93.7% of the patients. No patients needed rescue analgesia in recovery and no complications were recorded. Patient satisfaction was 93.7% and surgeon satisfaction was 97%.ConclusionsA selective block of the medial, ulnar and medial and lateral cutaneous nerves of the forearm are effective and satisfactory anaesthetic techniques for carpal tunnel release in a one-day case unit. It allows early mobilization, minimises risks and amount of local anaesthetic used.     

Single vs. double stimulation during a lateral sagittal infraclavicular block

Background: The objective of this study was to evaluate the influence of single vs. dual control during an ultrasound-guided lateral sagittal infraclavicular block on the efficacy of sensory block and the time of block onset.
Methods: In a prospective manner, 60 adult patients scheduled for distal upper limb surgery were randomly allocated to single (Group S) or double stimulation (Group D) groups. A local anesthetic (LA) mixture of 20 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml with 5 μg/ml epinephrine (total 40 ml) was administered in both groups. In the Group S following a median, an ulnar or a radial nerve response, the entire LA was administered at a single site. In Group D 10 ml of LA was administered following the electrolocation of the musculocutaneous nerve and 30 ml LA was injected following median, ulnar or radial nerves. A successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Sensory and motor blocks were tested at 5-min intervals for 30 min.
Results: The block was successful in 27 patients in Group S and 28 patients in Group D. The time from starting the block until satisfactory anesthesia was significantly shorter in Group D than in Group S (19.3 vs. 23.2 min) ( P <0.05). Total sensory scores were significantly higher in the double stimulation group at 20 and 30 min after the block performance ( P <0.05).
Conclusions: Although the block performance time was longer in the double stimulation group, block onset time and extent of anesthesia were more favorable in the double stimulation group.     

经皮电刺激内关穴监测拇内收肌神经肌肉阻滞的准确性

目的 评价经皮电刺激内关穴监测拇内收肌神经肌肉阻滞的准确性.方法 择期全麻下拟行腹部手术患者35例,年龄40～60岁,ASAⅠ～Ⅲ级,体重指数≤35 kg/m2.麻醉诱导完毕后所有患者行气管插管后机械通气,记录神经肌肉阻滞监测仪经内关穴与经尺神经监测的刺激强度和传感器的增益值;术中单次静脉注射阿曲库铵0.5 mg/kg,采用神经肌肉阻滞监测仪经内关穴与经尺神经监测的阿曲库铵起效时间、TOF比值(T4/T1比值)恢复至25%、90%的时间.结果 经皮电刺激尺神经和内关穴所得的电流强度及传感器的增益值差异无统计学意义(P>0.05);经皮电刺激尺神经和内关穴监测的阿曲库铵起效时间、TOF比值恢复至25%、90%的时间差异无统计学意义(P>0.05).结论 肌松监测仪的电极置于内关穴部位可准确地监测神经肌肉阻滞程度.     

不同浓度罗哌卡因用于臂丛神经感觉与运动分离阻滞的效果

目的 探讨不同浓度罗哌卡因用于臂丛神经感觉与运动分离阻滞的效果.方法 择期上肢手术患者90例,ASA分级Ⅰ～Ⅲ级,年龄16～75岁,体重40～85 kg.均在超声引导联合神经刺激器辅助定位下行腋路臂丛神经阻滞,根据不同罗哌卡因浓度分为3组(n=30):0.15%罗哌卡因组(A组),0.10%罗哌卡因组(B组),0.05%罗哌卡因组(C组).于注射局麻药后10、30、60、240 min(T1～4)时记录感觉与运动分离阻滞情况、感觉阻滞完善情况和臂丛神经阻滞成功情况,术毕时评定麻醉效果.记录手术时间、镇痛时间.结果 与A组比较,B组T1.2时感觉阻滞完善率较低(P＜0.05),T3.4时感觉阻滞完善率差异无统计学意义(P＞0.05),感觉与运动分离阻滞率较高(P＜0.01),C组T1.2时感觉与运动分离阻滞率较低(P＜0.01),T3.4时感觉与运动分离阻滞率差异无统计学意义(P＞0.05),各时点感觉阻滞完善率较低(P＜0.01).与B组比较,C组各时点感觉阻滞完善率、感觉与运动分离阻滞率均较低(P＜0.01).A组麻醉效果优于B组,B组麻醉效果优于C组(P＜0.01),与A组和B组比较,C组臂丛神经阻滞成功率较低(P＜0.01),A组与B组差异无统计学意义(P＞0.05).结论 0.10%罗哌卡因用于臂丛神经阻滞可产生感觉与运动分离阻滞效果.     

Blocks at the wrist using nerve stimulation for ambulatory hand surgery

One hundred and fifty-five patients were included in this prospective, open, multicenter study to examine the use of nerve stimulation to locate the median and ulnar nerves in ambulatory hand surgery. A sensory response was obtained in 65% of cases and a motor response in 65% with median nerve: the failure to elicit a motor response during median nerve stimulation was related to a higher failure rate of blocks (P = 0.041). A sensory response was reported in 63% and a motor response in 70% of the cases concerning the ulnar blocks: a sensory response was associated with greater success in the ulnar nerve (P = 0.01), while fourth and fifth fingers flexion increased the likelihood of failure (P = 0.075). This technique does not impair the organization of the surgical theatre (4 ± 3 min, mean ± S.D. block performance time) and 96% of patients were satisfied with the technique.     

The effect of intra‐operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy

Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra‐operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11‐point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra‐operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy.     

Speed of onset of 'corner pocket supraclavicular' and infraclavicular ultrasound guided brachial plexus block: a randomised observer-blinded comparison

This prospective, randomised, observer blinded study compared the onset time of brachial plexus block using 2% lidocaine 25–30 ml with adrenaline 5 μg.ml⁻¹ into the 'corner pocket' inferolateral/lateral to the subclavian artery (supraclavicular, n  = 30) or to a triple point injection around the axillary artery (infraclavicular, n  = 30). Mean (SD) onset time for complete pinprick sensory blockade assessed by a blinded observer in all four distal nerves was similar in both groups: supraclavicular = 22 (9.4) min, infraclavicular = 21 (7.1) min, p = 0.59. Complete sensory blockade in all four nerve territories at 30 min was achieved in 57% in group supraclavicular and 70% in group infraclavicular (p = 0.28). Painless surgery without the requirement for block supplementation was higher in group infraclavicular (28/30, 93%) compared with group supraclavicular (19/30, 67%; p = 0.01). Of the 11 failures in group supraclavicular, nine were due to incomplete ulnar nerve territory anaesthesia. These results do not support the concept of rapid onset successful supraclavicular block via a simple ultrasound-guided local anaesthetic injection inferolateral to the subclavian artery.